code: def min_train_series_length(self) -> int:
      return self.training_length + 1
  
imports: import inspect
  from abc import ABC, abstractmethod
  from typing import Optional, Sequence, Tuple, Type, Union
  import torch
  import torch.nn
  from darts.logging import get_logger, raise_if_not, raise_log
  from darts.models.forecasting.pl_forecasting_module import PLDualCovariatesModule, io_processor
  from darts.models.forecasting.torch_forecasting_model import DualCovariatesTorchModel
  from darts.timeseries import TimeSeries
  from darts.utils.data import DualCovariatesShiftedDataset, TrainingDataset
label_desc: Use image node_id 6 for calling the RNNModel obj's underlying member method code with example usage: obj.min_train_series_length() and returns: unknown